The present invention relates to a method and an apparatus for guiding the record carrier, i.e. sheet of paper in typewriters or similar office machines.
In office machines provided with an ink jet printer, it is necessary, in order to obtain a perfect recording, for the recording material to rest smoothly against the transporting element, e.g. the platen. For that reason, a special device is used to hold the recording material taut above the printing line. In such printers, paper pressing elements disposed after the printing location, when seen in the transporting direction of the platen, must be designed in such a manner that during the printing process they do not touch the paper during the time required for the ink to dry. Moreover, in such printers, which are designed for high operating speeds, the ink printing head is guided at a very close distance from the record carrier. The demands for accurate guidance of the record carrier in this region are therefore very high.
In one proposed arrangement, smearing of the not yet dry ink is avoided in that the pressure rollers are provided in the form of pressure rings and are disposed on a drive shaft in such a manner that they drive the paper by contacting it in the spaces between the printed characters. This type of paper transport may be suitable for recordings in which the characters have a certain spacing between one another. But in facsimile and proportional script recordings smearing of the not quite dry ink cannot be avoided with this proposed arrangement.
An arrangement disclosed in the IBM Disclosure Bulletin, Vol. 19, No. 3, August, 1976, page 754, includes an endless transporting belt for recording material printed by means of ink jet printers. This transporting belt is not made of a nonwettable or difficutly wettable material. Smearing of the not yet dry characters cannot be avoided here, either.